Gripping machine



Oct. Z7, 1953 v. J. HUGO ETAL 2,656,748

` GRIPPING MACHINE Filed sept. e, 1949 3 sneets-sheet 1 36 dit" III] L lll ATTORNEY Oct. 27, 1953 v. J. HUGO Erm. 2,556,748

GRIPPING MACHINE Filed Sept. 6, L949 5 Sheets-Sheet 2 Oct. 27, 1953 V, J. HUGO [g1-AL 2,656,748

GRIPPING MACHINE Filed Sept. 6, 1949 5 Sheets-Sheet 3 NVENTORS, VICTOR J. HUGO, JOHN A. MILLER 8| HARRY OTTINGER, DECEASED, BY EULALIA E. OTTINGER,

BY EXECUTRIX ATTORNEY Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE GRIPPING MACHINE tion of New Jersey Application September 6, 1949, Serial No. 114,214

4 Claims.

This invention relates to gripping machines, particularly machines for gripping articles while other operations are performed thereon.

Machines of the present invention are especially suited for gripping pipe lengths, for example, while threaded couplings or tool joints are applied thereto, although obviously machines that embody the same principles can be used for other purposes. Therefore, while we describe the machine in connection with gripping pipe, We do not wish to limit the invention to this particular use.

An object of the invention is to provide irn-l proved gripping machines which furnish a more positive and uniform grip on articles of varying dimensions within a tolerance range, than other machines with which we are familiar, and yet are of simple and rugged mechanical construction.

A further object of the invention is to provide improved machines for gripping articles in which the gripping elements are operated through a toggle linkage and a compensating mechanism, and in which the toggle linkage approaches its full extension when the elements are in gripping position irrespective of dimensional variations in the article, an arrangement which grips the article more positively and always with approximately the maximum mechanical advantage.

A further object of the invention is to provide gripping machines which have the foregoing improved features and in which the compensating mechanism automatically compensates for undersize dimensional variations in articles from the initial setting, thus insuring that the machine always grips articles vvith the same force and with approximately the maximum mechani cal advantage.

In accomplishing these and other objects of the invention, we have provided improved details of structure, preferred forms of which are shown in the accompanying drawings, in which:

Figure 1 is a transverse vertical sectional view of an improved gripping machine which embodies features of the present invention;

Figure 2 is a top plan view of the machine;

Figure 3 is a side elevational view of the machine, partly in section; and

Figure 4 is a vertical sectional view similar to Figure l, but showing a modification.

in Figures l, 2 and 3 of the drawings there is shown a gripping machine which comprises a base Il) and a frame I2, preferably supported for longitudinal sliding adjustment on said base. Said frame carries gripping elements which include a fixed gripping block I3 and a movable gripping block I4. These blocks have gripping jaws I5 and I6 respectively, which are removable and replaceable to accommodate different sizes and shapes of articles. The mounting for the movable block includes guideways I'I which extend transversely of the frame. The movable gripping element may be advanced on said guideways to a gripping position in which its jaw I6 cooperates with jaw I5 to engage an article, such as a pipe length P, or it can be retracted so that the article can be removed or inserted.

Frame I2 has a laterally extending shelf I3 on which is mounted the mechanism for operating the movable gripping element. The shelf has upstanding brackets I9 which have trunnions 20 that carry a toggle operating fluid pressure cylinder 2l, either hydraulic or pneumatic. A double-acting piston 22 is mounted for reciprocable movement in said cylinder and `carries a downwardly extending piston rod 23. A toggle mecha nism, hereinafter described, operatively connects the piston rod and the movable gripping block for advancing and retracting the latter. This ar rangement furnishes a large mechanical advan tage, so that the relatively low fluid pressures in the toggle operating cylinder are sufficient to operate the machine.

'I'he toggle mechanism includes back and front toggle links 24 and 25. One end of the back toggle link is pivoted at 25 to brackets I9 of the frame. The other end of the back toggle link is pivoted at 2'! to one end of the front toggle link and to the free end of piston rod 23. A set screw 28 is threadedly engaged in shelf I8 and furnishes a stop which engages the juncture between the toggle links when they are substantially at their position of alignment, but prevents their traveling beyond this position. The other end. of the front toggle link is pivcted to a collar 29,

An internally screw threaded sleeve 36 is jour naled in collar 29. The sleeve and collar carry cooperating latch means which normally prevent rotation of the sleeve. As illustrated, said latch means includes a dog 3i pivoted to the top of the collar and engageable with any one of a series of radial notches 32 in the end portion of the sleeve. A spindle 33 is threadedly engaged with sleeve 30 and carries a coupling 34, which is bolted to the movable gripping block.

Itis seen that lowering piston rod 23 extends toggle links 24 and 25 toward their position of alignment with each other where their mechanical advantage approaches its maximum. This movement advances spindle 33 and movable gripping block I4 and causes movable jaw I6 to cooperate with xed jaw I5 for gripping article P. The effective length of the spindle may be adjusted by releasing the latch mechanism and turning sleeve 3D.. Thisv adjustment tsthe ma.- chine to different sizes of articles and supplements the adjustment obtainable by use of different sizes of jaws I5 and I6. Initially the machine is adjusted so that, when the toggle links are substantially fully extended and their'juncture engages set screw 28, the movable. gripping element is spaced from the. fixedv gripping element a distance required to engage anarticle of predetermined dimensionsticles in which the tolerance range is. rather close, such as pipe lengths, this predetermined dimension can be the maximum oversize dimension within the tolerance range'. articles in which wider dimensional variations are encountered, such as rough castings, this predetermined dimension can be something less than the maximum oversize dimension (e. g. the nominal dimension). The toggle links themselves then furnish compensating means for gripping oversize articles.

According to the present invention, themachine has mechanism for positively compensating for undersize variations in the dimensions of articles P: from the predetermined. dimensionv of` the. initial setting. This mechanism insures that a constant pressure inthe toggleoperating cylinder always causes the jaws tofgrip an under.- sze articlev with. the same force and also that in gripping. position the toggle links always. are extended. substantially. totheir position of alignmenty where their mechanicalv advantage approaches its maximum.

Figures 1, 2 and 3 show a compensating mechanism which includes a collar 35 keyed to spindle 33 and having an integral upstanding arm 36. Shelf I8 has arearwardly extending bracket 31, to the top ofr which a fitting 38 is pivoted on a vert-ical axis (Figure 3). A compensating. fluid pressure cylinder 39 is pivoted to tting 38 onfa horizontal axis. The two axes of pivoting thus furnish a universal mounting for this cylinder. A double-acting piston andA piston rod 4U:

are mounted for reciprocable movementv in cylinder 39v and the end of the piston rod is pivoted to thev end of arm 36. of cylinder 3! enables this cylinder and piston rod 40 and collar 35A to travel with spindle 33 asv the toggle links are extended or retracted.

In the starting position piston rod 40 is retracted, but it has sufficient play inthe cylinder notv to interfere with longitudinal movement of spindle 33. After the toggle links are substantially fully extended and their juncture. engages set screw 28,v the compensating cylinder 39 can be actuated to project piston rod 40, which thus rotates collar 35- and spindle 33. Dog 3| holds sleeve 30 against rotation; hence, when the spindle rotates, it advances along its threaded connection with said sleeve. This movement advances the movable gripping block and jaw until the latter grips article P with the established gripping pressure. The pressure in the toggle operating cylinder is sufcient to overcome the back pressure on theV toggle links and prevent their buckling. Before the toggles are retracted, piston rod 40 and collar 35 are returned to their initial position.

Figure 4 shows a modified compensating mechanism inV which the coupling 34a whichV connectsl spindle 33 andI movable block. I4 slidably re- For gripping ar- For` gripping' The universal mounting.

45 and 46 which receive said wedge-shaped section. Passage 46 through said spindle contains an upwardly tapering shim 41. When the toggle links are. being extended, the wedge-shaped sectionof the rods acts merely to transmit movement of. the spindle to the coupling and the movable vgripping element. After the links are substantially fully extended and their juncture enga-ges set screw 28, piston rod 43 can be lowered and the Wedge surface of the rod cooperates with shim 47 to advance coupling 34a and the movablek gripping element with respect to thc spindle. Thus the gripping jaw grips article P with the established gripping pressure, as in the embodiment previously described.

From the foregoing. description, it is seen that machines of the present invention transmit pressure applied to the piston in the main cylinder through a toggle. linkage and that the mechanical advantage of this linkage approaches its maximum. when the gripping elements engage an article whose dimensions equal the initial spacing of the gripping elements when the toggle links are extended. The compensating mechanism insures that the machine applies a grip ofthe same force to articles whose dimensions are undersize from this initial spacing. For gripping articles whose dimensions are oversize from this initial spacing, the toggle links do not become as fully extended but still are extended sufliciently to furnish a substantial mechanical advantage.

While we have shown and described only certain preferred embodiments of the invention, it is apparent that other modications may arise. Therefore, we do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

We claim:

1. A machine for gripping articles whose dimensions vary within a tolerance range, said machine comprising a frame, fixed and movable gripping elements supported in said frame, a toggle operating fluid pressure cylinder pivoted to said frame, a double-acting piston and piston rod mounted for reciprocable movement in said cylinder, a toggle linkage pivoted to said frame and to said piston rod, a spindle interconnecting said toggle linkage and said movable gripping element and furnishing adjustment in the position said movable gripping element occupies when said toggle linkage is fully extended, a compensating iluid pressure cylinder, a doubleacting piston and piston rod mounted for reciprocable movement in said compensating cylinder, and means operatively connected with said second named piston rod for advancing and retracting said movable gripping element when said toggle linkage is substantially fully extended to compensate for dimensional variations in articles within the dimensional tolerance range for which the machine is adjusted.

2. A machine for gripping articles whose dimensions vary within a tolerance range, said machinecomprising a frame, xed and movable gripping elements supported in said frame, a toggle operating fluid pressure cylinder pivoted to said frame, a double-acting piston and piston rod mounted for reciprocable movement in said cylinder, |a toggle linkage pivoted to said frame and to said piston rod, a spindle interconnecting said toggle linka-ge and said movable gripping element and furnishing adjustment in the position said movable gripping element occupies when said toggle linkage is fully extended, a compensating fluid pressure cylinder universally pivoted to said frame, a ydouble-acting piston `and piston rod mounted for reciprocable movement in said compensating cylinder, and means operatively connecting said second named piston rod and -said spindle for advancing and retracting said movable gripping element when said toggle linkage is substantially fully extended to compensate for dimensional variations in articles within the dimensional tolerance range.

3. A machine for gripping articles Whose dimensions vary within a tolerance range, said machine comprising a frame, xed and movable gripping elements supported in said frame, a toggle operating fluid pressure cylinder pivoted to said frame, a double-acting piston and piston rod mounted for reciprocable movement in said cylinder, a toggle linkage lpivoted to said frame and to said piston rod, a collar pivoted to said toggle linkage, an internally screw threaded sleeve rotatably mounted in said collar, latch means normally connecting said collar iand said sleeve and thus preventing rotation of said sleeve, a spindle threadedly engaged in said sleeve and coupled with said movable gripping element, said piston being adapted to advance and retract said movable gripping element through said toggle linkage, stop means `engageable with said toggle link-age stopping movement thereof when said toggle linkage is in its position of substantially maximum mechanical advantage, a compensating fluid pressure cylinder universally pivoted to said frame, a double-acting piston and piston rod mounted for reciprocable movement in said compensating cylinder, and means operatively connecting said second named piston rod and said spindle for rotating said spindle relative to ls'aid sleeve and thereby advancing and retracting said movable gripping element when said toggle linkage is extended to its position of substantially maximum mechanical advantage to compensate for dimensional variations in articles within the dimensional tolerance range.

4. A machine for gripping articles whose di mensions vary Within a tolerance range, said machine comprising a frame, fixed and movable gripping elements supported in said frame, a toggle operating fluid pressure cylinder pivoted to said frame, a double-acting piston and ypiston rod mounted for reciprocable movement in said cylinder, a toggle linkage pivoted to said frame and to said piston rod, a spindle pivotally connected to said toggle linkage, a coupling xed to said movable gripping element and slidably receiving said spindle, said coupling and said spindle having aligned transverse passages, a compensating fluid Ipressure cylinder carried by said coupling, and a double-acting piston and piston rod mounted for reciprocable movement in said compensating cylinder, said second named piston rod having a wedge-shaped section received in said aligned transverse apertures for transmitting movement of said first named piston and said toggle linkage to said movable gripping element for advancing or retraeting the latter, actuation of said second named piston advancing and retracting s'aid movable gripping element and said coupling with respect to said spindle.

VICTOR J. HUGO. JOHN A. MILLER. EULALIA E. OTTINGER. Eecutrim of the estate of Harry Ottinger, de-

ceased.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 928,609 Kloeke July 20, 1909 1,416,970 Olson May 23, 1922 1,623,045 Butt Apr. 5, 1927 1,938,761 Fritschi Dec. 12, 1933 2,260,611 Di Santo Oct. 28, 1941 2,269,389 Weida Jan. 6, 1942 2,289,140 Mohan July 7, 1942 2,471,734 Fischer May 31, 1949 2,566,072 Snell Aug. 28, 1951 FOREIGN PATENTS Number Country Date 575,754 Great Britain Mar. 4, 1946 

